The present invention relates to a feeding device for moving and positioning an object at high speed and high precision in, e.g., various measurement apparatuses and a projection exposure apparatus used in a semiconductor lithography process.
FIG. 12 shows the arrangement of a conventional feeding device. In FIG. 12, reference numeral 51 denotes a stage base, on which a Y-stage 52 as a moving mechanism in the Y-direction (the direction perpendicular to the page) is arranged. Reference numeral 53 denotes a DC servo motor which converts rotational motion into rectilinear motion by a ball screw and drives the Y-stage 52. The DC servo motor 53 is fixed to the stage base 51. Reference numeral 54 denotes an X-stage arranged on the Y-stage 52; and 55, a DC servo motor which converts rotational motion into rectilinear motion by a ball screw 56 and drives the X-stage 54. The DC servo motor 55 is fixed to the Y-stage 52. Reference numeral 1 denotes a platen for holding the stage base 51.
Reference numerals 9a and 9b denote reflecting mirrors for a laser distance measuring device. The mirrors 9a and 9b are fixed to the X-stage 54. Reference numeral 8a denotes an interferometer of the laser distance measuring device, which detects the position of the X-stage 54 in the X-direction. The interferometer 8a is fixed to the platen 1 via an attachment frame 10. Reference numeral 13 denotes mount members for supporting the platen 1 and shielding vibrations transmitted from a floor on which the device is set.
In the above-mentioned arrangement, when the Y-stage 52 and the X-stage 54 are driven, the reaction force of the inertial force produced upon acceleration/deceleration is transmitted to the platen 1.
On the other hand, Japanese Patent Publication Laid-Open No. 05-077126 discloses an arrangement in which a moving stage that includes a platen supported by a platen support means with a low rigidity, a guide means arranged on the platen, a movable stage supported by the platen and the guide means, and a driving means, arranged on the platen, for giving a thrust to the movable stage, also includes a support means, independently of the platen, for supporting the driving means.
However, in the prior art shown in FIG. 12, when the support reaction force produced upon acceleration/deceleration of a moving object is transmitted to the platen 1, natural vibrations are excited in the mechanism system supported by the mount members 13, and disturbance vibrations are transmitted to the X-stage 54, Y-stage 52, laser interferometer 8a, and the like, thus disturbing high-speed, high-precision feeding.
On the other hand, in the prior art disclosed in Japanese Patent Publication No. 05-077126, the support reaction force produced upon acceleration/deceleration of a moving object is not transmitted to the platen that mounts the moving object. Nevertheless, the stage arrangement is limited.